During manufacture of a circuit board, electronic components and their interconnections are etched, imprinted, or otherwise attached to a substrate. The substrate and the electronic components are subsequently subjected to various processing steps. One particular processing step includes covering the circuit components and the underlying substrate with a sheet of silicone or other material that provides environmental and electrical protection.
Transfer molding is one process by which a protective material is applied over a circuit component. Another common process includes encapsulating the circuitry with silicone or another suitable material. The protective material is applied to the substrate as a liquid and then cured or otherwise hardened to form a solid coating. Although silicone and other suitable materials provide environmental, electrical, and mechanical protection to the encapsulated circuitry, there are some inherent difficulties and inefficiencies with commonly practiced encapsulation methods. For example, it can be difficult to supply a protective material that has sufficient fluidity to cover and infiltrate the circuitry, and at the same time has sufficient viscosity to set in the area immediately above and around the circuitry without spreading about the surrounding substrate.
One procedure that is aimed toward avoiding the difficulties of optimizing the consistency of an encapsulating material includes assembling a wall around the circuitry that is to be encapsulated. The wall is thin and rigid, and is shaped to surround the circuitry and to thereby barricade the encapsulating material. A few integral posts extend below the wall. When the circuit board is manufactured, the posts are press fitted into holes that are punched into the substrate around the circuit components that are to be encapsulated.
Although providing a wall around the circuit components is a beneficial step, there are some difficulties during and following the encapsulating process. For example, the assembly can be prone to leak around the punched post holes and at the interface between the substrate and the wall. The wall is also a cast molded structure, and cast molding individual walls can be a relatively expensive process. The wall can also impede some cost-efficient ways to apply the encapsulating material, such as a printing technique and the use of a squeegee. Further, subsequent substrate processing can be impeded by the wall's presence, particularly if the substrate is flexible. Additional electronic assemblies are sometimes combined with circuit components that remain exposed after the encapsulation procedure. The wall, or even a slightly warped substrate, can make it somewhat difficult to match some of the intricate electrical contacts between the additional electronic assemblies and the exposed circuit components.
Accordingly, it is desirable to provide a manufacturing process and apparatus that alleviates the difficulties associated with encapsulating an integrated circuit and any associated passive components on a substrate. In addition, it is desirable to provide a process and apparatus that does not impede subsequent substrate processing or electrical connections. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.